Read Write Map fields from Cassandra with Scala
In this little example, I show how to read and write Map columns in Cassandra. Cassandra table, here we have columns: ticker_id - ID of financial tool like EURUSD, ORCL, APPL, GOLD. ddate - simple date of DAY. ('2019-01-25','2019-01-26',...) CREATE TABLE mts_bars.td_bars_3600( ticker_id int, ddate date, bar_1 map , bar_2 map , bar_3 map , bar_4 map , bar_5 map , bar_6 map , bar_7 map , bar_8 map , bar_9 map , bar_10 map , bar_11 map , bar_12 map , bar_13 map , bar_14 map , bar_15 map , bar_16 map , bar_17 map , bar_18 map , bar_19 map , bar_20 map , bar_21 map , bar_22 map , bar_23 map , bar_24 map , PRIMARY KEY ((ticker_id), ddate) ) WITH CLUSTERING ORDER BY (ddate DESC); Primary key contains 2 columns, ticker_id and ddate ticker_id - is a PARTITION KEY, is responsible for data distribution across your nodes. ddate - is a Clustering Key, is responsible for...
